An organosilicon compound having an amino group has been known to be useful as a silane coupling agent, surface treating agent, fiber treating agent, adhesive, additive for a coating composition, and the like. More specifically, it has been known that, when an organosilicon compound having an amino group is added to an inorganic material (such as glass fiber, metal, or oxide filler) for the purpose of improving mechanical properties and heat resistance of the polymer material, the effect realized by the addition is enhanced by the improved bond between the polymer material and the inorganic material and improved dispersion of the inorganic material in the polymer material.
In contrast to silicon compounds having an aromatic group such as an aromatic amino group or aniline, the silicon compound having an aliphatic amino group has various merits in addition to the coupling properties as described above such as transparency in the range including UV range, extremely high solubility in water, and capability of use as an aqueous solution which leads to a very wide range of applications by a wide variety of method.
Silane coupling agent including the organosilicon compounds as described above are known to suffer from the problem of generating a considerable amount of alcohol in its use, and in particular, when it is blended in the polymer. Reduction of volatile organic compounds has become an urgent issue in view of global warming and health interests, and efforts have been made to reduce the amount of alcohol generated from the silane coupling agent as a contribution for such reduction of the volatile organic compounds. For example, amount of the alcohol generated in the use of the silane coupling agent is reduced in JP-A 2006-249069 by partly replacing alkoxyl group in the alkoxysilane with an involatile long chain alkyl polyether group, and in Japanese Patent No. 2962934 and JP-A 2002-226490, by producing a siloxane oligomer wherein the alkoxyl group is partly left intact by partly hydrolyzing and condensing the alkoxysilane.
However, production such organosilicon compounds developed for the purpose of reducing the alcohol suffered from various problems in their production, and in particular, when the alcohol is removed by distillation during their production as commonly carried out in producing an organosilicon compound. More specifically, purification by distillation was difficult due to the replacement with the involatile alkoxyl group or increase in the molecular weight due to intermolecular siloxane bond, and this invited decrease in the purity of the yielded product. In the production of such organosilicon compounds, the product was also in the form of a mixture, and this resulted in the insufficient stability of the physical properties. Accordingly, there is a strong demand for the production of an organosilicon compound having an amino group which can be readily purified, and which generates reduced amount of alcohol in its use.